U.S. patent number 8,035,566 [Application Number 12/436,125] was granted by the patent office on 2011-10-11 for multi-band antenna.
This patent grant is currently assigned to Cheng Uei Precision Industry Co., Ltd.. Invention is credited to Kai Shih, Jia-Hung Su, Yung-Chih Tsai, Yu-Yuan Wu.
United States Patent |
8,035,566 |
Tsai , et al. |
October 11, 2011 |
Multi-band antenna
Abstract
A multi-band antenna has a grounding plate with a first end and
a second end defined at a longer side thereof. The longer side has
an upward first connecting portion adjacent to the first end and a
vertical second connecting portion. A feeding portion extends
downwards from a lower edge of the second connecting portion. A
first antenna radiator extends towards a same direction with
respect to the second connecting portion along the grounding plate
from an upper side of the second connecting portion. A second
antenna radiator includes a first radiating portion, a second
radiating portion and a third radiating portion. A third antenna
radiator extends parallel to the first radiating portion from a
side of the feeding portion. A coupling component includes a first
section, a second section and a third section extending opposite to
the first section from an end of the second section.
Inventors: |
Tsai; Yung-Chih (Tu-Cheng,
TW), Su; Jia-Hung (Tu-Cheng, TW), Shih;
Kai (Tu-Cheng, TW), Wu; Yu-Yuan (Tu-Cheng,
TW) |
Assignee: |
Cheng Uei Precision Industry Co.,
Ltd. (New Taipei, TW)
|
Family
ID: |
43062065 |
Appl.
No.: |
12/436,125 |
Filed: |
May 6, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100283685 A1 |
Nov 11, 2010 |
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Current U.S.
Class: |
343/702; 343/846;
343/700MS |
Current CPC
Class: |
H01Q
5/371 (20150115); H01Q 9/0421 (20130101); H01Q
1/243 (20130101); H01Q 5/378 (20150115) |
Current International
Class: |
H01Q
1/24 (20060101) |
Field of
Search: |
;343/700MS,702,829,846 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Phan; Tho G
Claims
What is claimed is:
1. A multi-band antenna, comprising: an elongated grounding plate
disposed levelly with a first end and a second end defined at a
longer side thereof, the longer side having an upward first
connecting portion adjacent to the first end, a vertical second
connecting portion extending along the longer side and opposite to
the first end from an upper portion of the first connecting portion
and being spaced away from the grounding plate; a feeding portion
extending downwards from a lower edge of the second connecting
portion, and spaced away from the grounding plate; a first antenna
radiator extended towards a same direction with respect to the
second connecting portion along the grounding plate from an upper
side of the second connecting portion, the first antenna radiator
parallel to the grounding plate and elongated along an extending
direction of the grounding plate; a second antenna radiator, the
second antenna radiator including a first radiating portion
extended towards the second end from a side of the second
connecting portion facing the second end and longer than the first
antenna radiator, a second radiating portion extended upwards from
a free end of the first radiating portion, and a third radiating
portion prolonged opposite to the first radiating portion from a
top end of the second radiating portion, the third radiating
portion substantially flush and aligned with the first antenna
radiator; a third antenna radiator parallel to the first radiating
portion and connected to a side of the feeding portion extending
toward the second end; and a coupling component connected with the
second end of the longer side and including a first section
extending towards the third radiating portion, with a top edge
lower than the third radiating portion, a second section extending
perpendicularly and away from the third radiating portion from a
free end of the first section, and a third section extending
opposite to the first section from a free end of the second section
and beyond the third radiating portion.
2. The multi-band antenna as claimed in claim 1, wherein the longer
side of the grounding plate has a portion extended outwards and
bent upwards to form the first connecting portion of L shape, the
second connecting portion is extended from an end of the first
connecting portion, having an upwardly oriented end away from the
first connecting portion to show an L-shape, the feeding portion
with a bent bottom adjacent to the grounding plate is spaced away
from the first connecting portion.
3. The multi-band antenna as claimed in claim 2, wherein the longer
side of the grounding plate has a portion extended upwards to form
a soldering portion between the first connecting portion and the
feeding portion, the soldering portion is spaced from the first and
second connecting portions with a predetermined distance.
4. The multi-band antenna as claimed in claim 1, wherein the first
end and the second end of the longer side are extended upwards to
form a first positioning plate and a second positioning plate,
respectively, each of which has two positioning holes for
convenient assembly.
5. The multi-band antenna as claimed in claim 4, wherein the first
section of the coupling component is extended from a side of the
second positioning plate facing the first positioning plate.
6. The multi-band antenna as claimed in claim 1, wherein the third
antenna radiator protrudes slantingly and downwardly a distance,
and extends parallel to the first radiating portion, a bottom edge
and a free end of third antenna radiator are respectively and
substantially flush with the grounding plate and a free end of the
first antenna radiator.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a multi-band antenna, and particularly to
a multi-band antenna with a compact structure capable of covering
multiple frequency bands.
2. The Related Art
With the development of electronic technology, a portable
communication electronic device is generally equipped with many
antennas for supporting wireless communication in multiple
operating frequency bands, such as the bands of Global Position
System (GPS), wireless wide area network (WWAN) and the like,
nowadays. Accordingly, it makes the electronic device occupy a
relatively large space to receive the corresponding antennas, which
is against the current trends of light and compact electronic
device; furthermore, it increases the manufacturing cost and the
assembling time. So it is necessary to design an antenna with a
compact structure capable of covering the above-mentioned frequency
bands synchronously.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a multi-band
antenna with a compact structure capable of covering multiple
frequency bands.
The multi-band antenna has an elongated grounding plate disposed
levelly with a first end and a second end defined at a longer side
thereof. The longer side has an upward first connecting portion
adjacent to the first end and a vertical second connecting portion
extending along the longer side and opposite to the first end from
an upper portion of the first connecting portion and being spaced
away from the grounding plate. A feeding portion extends downwards
from a lower edge of the second connecting portion, and is spaced
away from the grounding plate. A first antenna radiator extends
towards a same direction with respect to the second connecting
portion along the grounding plate from an upper side of the second
connecting portion. The first antenna radiator is parallel to the
grounding plate and elongated along an extending direction of the
grounding plate. A second antenna radiator includes a first
radiating portion extended towards the second end from a side of
the second connecting portion facing the second end and longer than
the first antenna radiator, a second radiating portion extended
upwards from a free end of the first radiating portion, and a third
radiating portion prolonged opposite to the first radiating portion
from a top end of the second radiating portion. The third radiating
portion is substantially flush and aligned with the first antenna
radiator. A third antenna radiator extends parallel to the first
radiating portion from a side of the feeding portion extending
toward the second end. A coupling component connected with the
second end of the longer side includes a first section extending
towards the third radiating portion, with a top edge lower than the
third radiating portion, a second section extending perpendicularly
and away from the third radiating portion from a free end of the
first section, and a third section extending opposite to the first
section from a free end of the second section and beyond the third
radiating portion.
As described above, the first antenna radiator, the second antenna
radiator, the third antenna radiator and the coupling component are
adapted for generating electromagnetic resonance in frequency bands
ranging from 1710 MHz to 2170 MHz, from 824 MHz to 960 MHz and
around 1575 MHZ, respectively. Thus the multi-band antenna is
capable of receiving and sending electromagnetic signals in GSM850
(824.about.894 MHZ), GSM900 (880.about.960 MHZ), GPS (1575.+-.10
MHZ), DCS (1710.about.1880 MHZ), PCS (1850.about.1990 MHZ) and
W-CDMA 2100 (1920.about.2170 MHZ). Therefore, the multi-band
antenna covering multiple frequency bands mainly used in the world
will meet the using demands from customers and be inclined to be
applied widely.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be apparent to those skilled in the art
by reading the following description thereof, with reference to the
attached drawings, in which:
FIG. 1 is a perspective view of a multi-band antenna according to
an embodiment of the present invention;
FIG. 2 is a perspective view of the multi-band antenna shown in
FIG. 1 seen from another direction;
FIG. 3 is a Smith chart recording impedance of the multi-band
antenna shown in FIG. 1;
FIG. 4 shows a Voltage Standing Wave Ratio (VSWR) test chart of the
multi-band antenna shown in FIG. 1;
FIG. 5 shows a Return Loss test chart of the multi-band antenna
shown in FIG. 1; and
FIG. 6 shows an Antenna Performance test chart of the multi-band
antenna shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Please refer to FIG. 1 and FIG. 2, a multi-band antenna according
to the present invention is shown. The multi-band antenna mounted
on an electronic device (not shown) has an elongated grounding
plate 10 disposed levelly with a longer side 11 defined thereon.
Both opposite ends of the longer side 11 is defined a first end 111
and a second end 112. The first end 111 and the second end 112 are
both extended upwards to form a first positioning plate 12 and a
second positioning plate 13. Each of the first positioning plate 12
and the second positioning plate 13 has two positioning holes 14,
convenient for assembly. An upward first connecting portion 15 is
extended outwards from a portion of the longer side 11 adjacent to
the first positioning plate 12 and bent upwards to show an L-shape.
A vertical second connecting portion 16 is extended opposite to the
first positioning plate 12 along the longer side 11 from an upper
portion of the first connecting portion 15. The second connecting
portion 16 is of L-shape, having an upwardly oriented end, and
spaced away from the grounding plate 10. A feeding portion 17
extends downwards from a lower edge of the second connecting
portion 16, with a bent bottom adjacent to and spaced apart from
the grounding plate 10. A soldering portion 18 extends upwards from
a portion of the longer side 11 of the grounding plate 10 between
the first connecting portion 15 and the feeding portion 17, and is
spaced away from the first and the second connecting portions 15,
16 with a predetermined distance for generating coupling effect
therebetween, enlarging frequency width of the multi-band antenna.
The soldering portion 18 is biased from the second connecting
portion 16 and adapted for soldering a cable (not shown) thereon. A
first antenna radiator 20 extends towards a same direction with
respect to the second connecting portion 16 along the grounding
plate 10 from an upper side of the oriented end of the second
connecting portion 16. The first antenna radiator 20 is parallel to
the grounding plate 10 and elongated along an extending direction
of the grounding plate 10. A second antenna radiator 30 includes a
first radiating portion 31 extended towards the second positioning
plate 13 from a lower portion of a side of the second connecting
portion 16 facing the second end 112 and longer than the first
antenna radiator 20, a second radiating portion 32 extended upwards
from a free end of the first radiating portion 31, and a third
radiating portion 33 prolonged levelly and opposite to the first
radiating portion 31 from a top edge of the second radiating
portion 32. The third radiating portion 33 is substantially flush
and aligned with the first antenna radiator 20. A third antenna
radiator 40 extending from a side of the feeding portion 17
protrudes slantingly and downwardly toward the second end 112, and
then extends parallel to the first radiating portion 31. A bottom
edge and a free end of the third antenna radiator 40 are
respectively and substantially flush with the grounding plate 10
and a free end of the first antenna radiator 20. A coupling
component 50 includes a first section 51 extended towards the third
radiating portion 33 of the second antenna radiator 30 from a side
of the second positioning plate 13 facing the first positioning
plate 12, with a top edge lower than the third radiating portion 33
and a free end spaced from the third radiating portion 33 with a
short distance, a second section 52 extended perpendicularly and
away from the third radiating portion 33 from a free end of the
first section 51, and a third section 53 extended perpendicularly
and opposite to the first section 51 from a free end of the second
section 52 and beyond the third radiating portion 33.
When the multi-band antenna operates at wireless communication, a
current is fed from the feeding portion 17 to the first antenna
radiator 20 to generate an electrical resonance corresponding to
frequency band ranging between 1.71 GHz and 2.17 GHz. While the
current is fed from the feeding portion 17 to the second antenna
radiator 30 to generate an electrical resonance corresponding to
frequency band ranging between 824 MHz and 960 MHz. Meanwhile, the
first antenna radiator 20, the second antenna radiator 30 and the
third antenna radiator 40 have influence upon each other, so that
the electrical resonance according to the frequency bands are
superimposed, consequently, enlarging bandwidth of a high
frequency. The coupling portion 50 and the third radiating portion
33 of the second antenna radiator 30 generate coupling effect
therebetween, which can generate an electrical resonance
corresponding to frequency band of 1575 MHZ.
Please refer to FIG. 3, which shows a Smith chart recording
impedance of the multi-band antenna when the multi-band antenna
operates at wireless communication. The multi-band antenna exhibits
an impedance of (96.767+j43.694) Ohm at 824 MHz, an impedance of
(26.284-j8.061) Ohm at 960 MHz, an impedance of (49.271+j2.808) Ohm
at 1575 MHz, an impedance of (59.414+29.240) Ohm at 1710 MHz, an
impedance of (32.815+j0.2289) Ohm at 2170 MHz. Therefore, the
multi-band antenna has good impedance characteristics.
Please refer to FIG. 4, which shows a Voltage Standing Wave Ratio
(VSWR) test chart of the multi-band antenna when the multi-band
antenna operates at wireless communication. When the multi-band
antenna operates at 824 MHz (indicator Mkr1 in FIG. 4), the VSWR
value is 2.469. When the multi-band antenna operates at 960 MHz
(indicator Mkr2 in FIG. 4), the VSWR value is 2.031. When the
multi-band antenna operates at 1575 MHz (indicator Mkr3 in FIG. 4),
the VSWR value is 1.062. When the multi-band antenna operates at
1.71 GHz (indicator Mkr4 in FIG. 4), the VSWR value is 1.575. When
the multi-band antenna operates at 2.17 GHz (indicator Mkr5 in FIG.
4), the VSWR value is 1.539. The VSWR values of the multi-band
antenna show that the multi-band antenna has an excellent frequency
response between 825 MHz.about.960 MHz, between 1.71 GHz.about.2.17
GHz, and 1575 MHZ.
Please refer to FIG. 5, which shows a Return Loss test chart of the
multi-band antenna when the multi-band antenna operates at wireless
communication. When the multi-band antenna operates at 824 MHz
(indicator Mkr1 in FIG. 5), the return loss value is -7.751 dB.
When the multi-band antenna operates at 960 MHz (indicator Mkr2 in
FIG. 5), the return loss value is -9.385 dB. When the multi-band
antenna operates at 1575 MHz (indicator Mkr3 in FIG. 5), the return
loss value is -31.518 dB. When the multi-band antenna operates at
1.71 GHz (indicator Mkr4 in FIG. 5), the return loss value is
-11.277 dB. When the multi-band antenna operates at 2.17 GHz
(indicator Mkr5 in FIG. 5), the return loss value is -13.643 dB.
The return loss values of the multi-band antenna show that the
multi-band antenna has an excellent frequency response between 825
MHz.about.960 MHz and between 1.71 GHz.about.2.17 GHz and 1575
MHZ.
Please refer to FIG. 6, which shows an efficient chart of the
multi-band antenna in the embodiment. When the multi-band antenna
receives and sends electromagnetic signals in GSM 850
(824.about.894 MHZ), the average antenna efficient is 38.94%. When
the multi-band antenna receives and sends electromagnetic signals
in GSM 900 (880.about.960 MHZ), the average antenna efficient is
43.19%. When the multi-band antenna receives and sends
electromagnetic signals in GPS (1575.+-.10 MHZ), the average
antenna efficient is 35.78%. When the multi-band antenna receives
and sends electromagnetic signals in DCS (1710.about.1880 MHZ), the
average antenna efficient is 33.98%. When the multi-band antenna
receives and sends electromagnetic signals in PCS (1850.about.1990
MHZ), the average antenna efficient is 33.17%. When the multi-band
antenna receives and sends electromagnetic signals in W-CDMA 2100
(1920.about.2170 MHZ), the average antenna efficient is 33.14%. The
average antenna efficient shows that the multi-band antenna has a
good performance in the low frequency and the high frequency.
As described above, the structure of the multi-band antenna is
simple and compact. The first antenna radiator 20, the second
antenna radiator 30, the third antenna radiator 40 and the coupling
component 50 are capable of covering frequency bands between 824
MHZ and 960 MHZ, between 1710 MHZ and 2170 MHZ and around 1575 MHZ,
which makes the multi-band antenna capable of receiving and sending
electromagnetic signals in GSM850 (824.about.894 MHZ), GSM900
(880.about.960 MHZ), GPS (1575.+-.10 MHZ), DCS (1710.about.1880
MHZ), PCS (1850.about.1990 MHZ) and W-CDMA 2100 (1920.about.2170
MHZ). Therefore, the multi-band antenna covering multiple frequency
bands mainly used in the world and occupying a less space will meet
the using demands from customers and be inclined to be applied
widely.
Furthermore, the present invention is not limited to the embodiment
described above; various additions, alterations and the like may be
made within the scope of the present invention by a person skilled
in the art. For example, respective embodiments may be
appropriately combined.
* * * * *